JPH0781929A - Silicon dioxide coating film producing device - Google Patents

Abstract

PURPOSE:To remove adhered particles and obtain a high quality silicon dioxide coating film by providing a switching valve having an inlet hole and an outlet hole to introduce and discharge a liq., etc., in the circulating line of a processing soln. contg. silicon dioxide, etc., of the specified device. CONSTITUTION:A treating tank 1 is filled with a processing soln. 2 contg. a hydrosilicofluoric acid soln., etc., a substrate 3 to be treated is set, and a circulating means 5 and a filtration means 6 are arranged between the tank 1 and a processing soln. regulating tank 4. Three-way valves V1, V2, V3 and V4 provided with an inlet hole 17a for introducing liq. or gas into a clearance 18 on the periphery of the valve disk of the switching valve from outside and an outlet hole 17b for discharging the liq. or gas are furnished to a main circulating line 8. The processing soln. is introduced into a passage 15c from an inlet 20, passed through the passages 16c and 16a in the valve disk 12 and discharged into an outlet 21 from a passage 15a. Meanwhile, a desired cleaning soln., etc., are introduced form the inlet hole 17a to wash away the silicon dioxide coating film deposited in the clearance 18 and discharged from the outlet hole 17b to constitute the silicon dioxide coating film producing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon dioxide coating manufacturing apparatus, and more particularly, to a silicon wafer on a substrate to be processed such as a semiconductor wafer or a glass substrate in a semiconductor manufacturing process or a manufacturing process of electronic parts such as a liquid crystal display device. The present invention relates to an apparatus for producing a silicon dioxide film that produces a film from a liquid phase.

[0002]

2. Description of the Related Art A liquid phase film forming method (LP
Since the method D) can form a film at a temperature near room temperature and has a good followability even on a submicron level surface irregularity, a film with a uniform thickness and few defects can be obtained. There is. The liquid phase film forming method of this silicon dioxide film is
For example, JP-A-60-33233 and JP-A-62-2
It is proposed by Japanese Patent Publication No. 0876.

FIG. 6 is an explanatory view showing a device configuration of a device for producing a silicon dioxide film by a liquid phase film forming method. The processing tank 1 is loaded with a semiconductor substrate or a glass substrate which is the substrate 3 to be processed, and is immersed in a processing liquid 2 containing a hydrosilicofluoric acid solution in a supersaturated state of silicon dioxide. , A silicon dioxide film is deposited. In the treatment liquid adjusting tank 4, in order to maintain the supersaturated state of the silicon dioxide of the treatment liquid 2, the active material 7 such as aluminum or boric acid is dissolved.

When a substrate 3 to be processed, for example, a semiconductor wafer is immersed in a treatment liquid 2 containing silicon dioxide in a supersaturated state and a silicon dioxide film is formed on the surface thereof, particles of silicon dioxide or the like precipitated in the treatment liquid 2. Grows and coarsens, and floats in the processing liquid 2 as so-called dust. Further, particles such as silicon dioxide are deposited in the treatment liquid 2 during film formation and adhere to the inner wall of the treatment tank 1, the inner wall of the pipe passage, the inner wall of the treatment liquid adjusting tank 4, and the like. As the film formation progresses, particles are further deposited on the particles attached to the wall surface, and the film of the particle layer attached to the wall surface gradually becomes thicker. When the particle layer adhering to the inner wall of the tank or the inner wall of the pipe is peeled off, it also becomes dust floating in the treatment liquid 2. This dust often adheres to the surface of the wafer and becomes a defect in the silicon dioxide film, often lowering the yield of semiconductor devices.

Therefore, in order to remove dust such as silicon dioxide particles in the treatment liquid 2, a circulation means 5 and a filtration means 6 are provided to circulate and filter the treatment liquid 2. The circulation means 5 has no pulsation and does not adversely affect the filtration.
Also, a pump is used which has a relatively large circulation flow rate. A filter having a pore size of about 0.05 to 1 μm is used as the filtering means. Further, a cleaning device is incorporated in the filter, and when the filter is clogged, it is automatically cleaned.

However, in the above-mentioned apparatus configuration for forming a silicon dioxide film from a liquid phase, the film forming rate is slow, and it takes a very long time to form a film at a film forming rate of, for example, 10 to 20 Å / min. Resulting in. When the film forming speed is low as described above, the inner wall of the tank or the inner wall of the conduit is considerably contaminated by the adhered particle layer of silicon dioxide and the like when the film forming process is performed once. For this reason, the filter is clogged and clogged during one film formation. Therefore, as shown in FIG. 2, two filters 11 and 12 are prepared for the filters (F ₁ and F ₂ ) and they are switched and used alternately. Is being done. That is, for example, when the filter F ₁ of the first system 11 is used, the processing liquid is circulated by setting the _three- way valves V ₁ and V ₃ on the circulation casing 8 side. Meanwhile, the filter F ₂ of the second system 12 is washed. For cleaning the filter F _2, a cleaning liquid such as hydrofluoric acid is introduced from the cleaning liquid inlet A, and is discharged from the three-way valve V ₄ to the cleaning liquid outlet B through the three-way valve V ₂ and the filter F ₂ . And
If the filter F ₁ in use is clogged due to clogging, the three-way valves V ₂ and V ₄ are switched to the processing liquid circulation path 8 side, and the three-way valves V ₁ and V ₃ are respectively set to the cleaning liquid inlet A and the cleaning liquid outlet B. Then, the treatment liquid 2 is filtered by the filter F ₂ and the filter F ₁ is washed during that time.

FIG. 7 shows such a conventional three-way switching valve V ₁ , V
Shows an example of _2, V _3, V ₄ structure, (A) is a longitudinal sectional view, (B) is a cross-sectional view taken along the CC line.
The valve box 11 is provided with a valve body 12 that switches the flow path of the processing liquid via a minute gap portion 18. The valve box 11 includes processing liquid passages 15a, 15b, and 15c. On the other hand, the valve body 12 also includes processing liquid passages 16a, 16b, 16c. The valve shaft 13 switches the flow path of the processing liquid. In the state shown in the drawing, the processing liquid inlet 20 is connected to the passages 15c, 16c, 1
It communicates with the processing liquid outlet 21 through 6a and 15a. By rotating the valve shaft 13 by 90 ° C., the processing liquid inlet 2
The flow path can be switched from 0 to the processing liquid outlet 22 through the passages 16b and 15b. The minute gap portion 18 between the valve body 12 and the valve box 11 is sealed by the O-ring 14 to prevent the processing liquid from entering the minute gap portion 18 on the outer peripheral portion of the valve body.

[0008]

However, the valve shaft 1
When the flow path of the processing liquid is switched by rotating 3, the processing liquid passages 16a, 16b, 16c instantaneously come into contact with the outer peripheral portion of the valve body outside the seal by the O-rings 14, The processing liquid will fill the minute gap portion 18. The treatment liquid filled in the minute gap portion 18 sealed by the O-ring 14 deposits silicon dioxide particles, and the coating of the deposited particle layer impairs the movement of the valve body and makes it difficult to switch the valve body. And often stopped the equipment. Further, even if the valve body is switched, the O-ring is damaged by the coating of the silicon dioxide particle layer deposited in the gap between the valve body and the valve box, and the processing liquid leaks to other circuits, and the peeled coating film is removed. When mixed in the treatment liquid, particularly in the valve downstream of the filter, it flows into the treatment tank 1 and adheres to the substrate to be treated, which impedes uniform film formation.

The present invention has been made in view of the above problems of the prior art, and provides an apparatus for producing a silicon dioxide film capable of forming a high-quality silicon dioxide film by smoothing the operation of a switching valve. The purpose is to do.

[0010]

SUMMARY OF THE INVENTION An apparatus for producing a silicon dioxide film according to the present invention comprises a treatment liquid containing a hydrosilicofluoric acid solution in which silicon dioxide is supersaturated, and the treatment liquid being brought into contact with a substrate to be treated. Processing tank for depositing a silicon dioxide film on the surface of the substrate, a processing solution adjusting tank for dissolving an active material to maintain a supersaturated state of the silicon dioxide of the processing solution, the processing solution, and the processing tank In the apparatus for producing a silicon dioxide film, which comprises a circulation means for circulating the liquid in the liquid adjusting tank and a filtration means arranged in the circulation path of the treatment liquid, the circulation path includes:
It has a switching valve that switches the flow direction of the flow path to one direction or a plurality of directions, and the switching valve used at all or a part of the switching valve is a liquid or gas from the outside to the inner peripheral portion of the switching valve body. It is characterized by having an introduction hole for guiding and a discharge hole for discharging the liquid or gas introduced from the introduction hole.

[0011]

With the introduction hole for guiding the outer peripheral portion of the switching valve valve body and the discharge hole for discharging the liquid or gas introduced from the introduction hole, the outer peripheral portion of the switching valve valve body is cleaned. It becomes possible. Therefore, even if the film of the particle layer is deposited on the outer peripheral portion of the valve body due to the switching of the switching valve, the deposited particle layer can be removed by washing, and the malfunction of the switching valve or the peeled coating may be contained in the treatment liquid. It is possible to prevent the problem of mixing and releasing dust.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to fourth embodiments of the present invention will be described with reference to the attached FIGS. In this embodiment, a treatment tank 1 for depositing a silicon dioxide film on a substrate 3 to be treated from a treatment liquid 2 containing a hydrosilicofluoric acid solution in which silicon dioxide is supersaturated, and a supersaturated state of silicon dioxide in the treatment liquid are shown. Treatment liquid adjustment tank 4 for dissolving active material to maintain
It is the same as in the conventional technique that it is provided with the circulating means 5 for circulating the processing liquid between the processing tank 1 and the processing liquid adjusting tank 4, and the filtering means 6 arranged in the circulation path of the processing liquid.

Three-way switching valves V ₁ , V ₂ , V of the first embodiment
Reference numerals ₃ and V ₄ are introduction holes 17a for introducing liquid or gas from the outside into the gap 18 at the outer peripheral portion of the internal switching valve body as shown in FIG. 1 and discharge holes for discharging the introduced liquid or gas. 17b is provided. Other components are shown in FIG.
This is the same as the conventional switching valve shown in FIG. 3, and the same or corresponding components are designated by the same reference numerals and the description thereof will be omitted.

As shown in the figure, in addition to the processing liquid inlet 20 and the processing liquid outlets 21 and 22, the three-way switching valve is provided with two points, an inlet port 17a and an outlet port 17b, which are inlets and outlets for the cleaning liquid. (Gas) is applied to the gap portion 18 on the outer peripheral portion of the valve body.
The silicon dioxide particle layer that has been poured into and is precipitated can be washed out. Next, the operation of the three-way switching valve of this embodiment will be described. In the state shown in FIG. 1, the processing liquid flowing from the processing liquid inlet 20 enters through the passage 15c, passes through the passages 16c and 16a in the valve body 12, and passes through the passage 1
The processing liquid exits from 5a. During this time, a separate cleaning liquid such as hydrofluoric acid (which may be a gas for cleaning purposes) enters through the introduction hole 17a, rinses away the silicon dioxide film deposited in the gap portion 18 at the outer peripheral portion of the valve body, and discharges it through the discharge hole 17b. Discharge and stop the flow of cleaning liquid when it is completely clean. If the valve body 12 is switched by rotating the valve shaft 13 after the cleaning of the outer peripheral portion of the valve body, the valve body can be smoothly rotated without damaging the O-ring 14 that seals the clearance. Therefore, the processing liquid flowing from the processing liquid inlet 20 can be smoothly switched to the outlet 22,
It is possible to form a high-quality silicon dioxide film on the target substrate 3 in the processing tank 1 without mixing dust in the processing liquid.

FIG. 2 shows a three-way switching valve according to the second embodiment of the present invention. In the three-way switching valve of this embodiment, the gap portion 23 on the outer peripheral portion of the valve body is larger than that of the first embodiment as shown in the drawing. Further, a portion where the processing liquid flows and a portion where the cleaning liquid (gas) introduced from the outside flows are blocked by a minute gap 24 between the valve body and the valve box. Since the gap portion 23 on the outer peripheral portion of the valve body is enlarged, the cleaning liquid (gas) can be easily flowed and the cleaning is facilitated. or,
Since the minute gap is used to block between the portion where the processing liquid flows and the portion where the cleaning liquid (gas) flows, sealing by an O-ring or the like becomes unnecessary.

FIG. 3 shows a three-way switching valve according to the third embodiment of the present invention. The switching valve of the present embodiment has a portion through which the processing liquid flows,
The part where the cleaning liquid (gas) introduced from the outside flows
O-ring 25 mounted on the valve body 12 side or the valve box 11 side
Is blocked by. Gap portion 23 on the outer peripheral portion of the valve body
Is large as in the second embodiment. Therefore, the outer peripheral portion of the valve body can be easily cleaned as in the second embodiment. Further, since the outer peripheral portion of the valve body is sealed by the O-ring 25, the valve body 12 can be rotated more smoothly.

FIG. 4 shows a three-way switching valve according to the fourth embodiment of the present invention. The switching valve of this embodiment is a sliding type switching valve,
(A) shows a state in which the processing liquid flowing from the processing liquid inlet 20 flows to the processing liquid outlet 21. (B) shows a state in which the processing liquid flowing from the processing liquid inlet 20 is switched to the processing liquid outlet 22 and flows. In the state of (A), the sliding portion 2 of the valve body 30
Since 6 blocks the passages 15a and 15c, the processing liquid flowing in from the processing liquid inlet 20 flows out to the processing liquid outlet 21. On the other hand, when the valve shaft 13 moves, as shown in (B), the sliding portion 26 of the valve body 30 closes the passages 15a and 15b, so that the processing liquid flowing from the processing liquid inlet 20 is processed by the processing liquid outlet 22. Is switched to.

Also in this embodiment, the valve body 30 has the sliding portion 2
Except for 6, a gap portion 27 is provided. And the valve box 11
Is provided with an inlet 17a and an outlet 17b for the cleaning liquid,
In addition, a communication hole 29 that connects the clearance portion 19 and the clearance 27 of the valve body is provided. Therefore, a cleaning liquid (gas) such as hydrofluoric acid is made to flow from the introduction hole 17a to the discharge hole 17b through the gap 19, the conduction hole 29, the sliding valve gap 27, the conduction hole 29, the sliding valve gap 27, etc. It is possible to clean the clearance around the outer periphery of the valve.

FIG. 5 shows an embodiment of an apparatus for producing a silicon dioxide film using the three-way switching valve of the present invention. 3-way switching valve V
_{1, V 2, V 3,} V 4 , the introduction hole 17a and the discharge hole 17b of the respective valve body is connected to a cleaning liquid inlet A and outlet B. Therefore, in addition to the flow path of the processing liquid, the outer peripheral portion of the valve body can be cleaned independently of the flow path of the processing liquid by the cleaning liquid (gas) flowing from the cleaning liquid inlet A to the outlet B.

Although the above description has been made by taking a three-way switching valve as an example, it goes without saying that the technical idea of the present invention can be applied to a two-way valve, a four-way valve, etc. without being limited to the embodiments. . The same reference numerals in the drawings indicate the same or corresponding constituent elements.

[0021]

As described above, according to the switching valve of the present invention, the particle coating adhered to the outer peripheral portion of the valve body can be washed and removed. Therefore, the operation of the switching valve of the silicon dioxide film manufacturing apparatus can be made smooth and a high-quality silicon dioxide film can be formed.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the structure of a three-way switching valve according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing the structure of a three-way switching valve of a second embodiment of the present invention.

FIG. 3 is an explanatory view showing the structure of a three-way switching valve of a third embodiment of the present invention.

FIG. 4 is an explanatory diagram showing the structure of a three-way switching valve according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a device configuration of a silicon dioxide film manufacturing apparatus according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a device configuration of a conventional silicon dioxide film manufacturing apparatus.

FIG. 7 is an explanatory view showing the structure of a conventional three-way switching valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Processing tank 2 Processing liquid 3 Processing substrate 4 Processing liquid adjusting tank 5 Circulating means 6 Filtration means 8 Main circulation path 11 Valve box 12 Valve body 17a Introducing hole 17b Discharging hole 18, 23, 27 Gap part of outer peripheral part of valve body 20 treatment liquid inlet 21 and 22 the processing liquid outlet _{V 1, V 2, V 3} , V 4 way valve A cleaning liquid inlet B washing liquid outlet

Claims (3)

[Claims] 1. A treatment solution containing a hydrosilicofluoric acid solution in which silicon dioxide is supersaturated, and a treatment tank for bringing the treatment solution into contact with a substrate to be treated to deposit a silicon dioxide film on the surface of the substrate. A treatment liquid adjusting tank for dissolving an active material in order to maintain the supersaturated state of silicon dioxide in the treatment liquid, a circulation means for circulating the treatment liquid between the treatment tank and the treatment liquid adjusting tank, and circulation of the treatment liquid In the apparatus for producing a silicon dioxide film provided with a filtering means arranged in a passage, the circulation passage has a switching valve for switching the flow direction of the passage to one direction or a plurality of directions, and all or all of the switching valves. The switching valve used in some places has an introduction hole for guiding liquid or gas from the outside to the outer peripheral portion of the internal switching valve body, and a discharge hole for discharging the liquid or gas introduced from the introduction hole. Silicon dioxide characterized by having Coating of the manufacturing apparatus. 2. The switching valve is configured such that a portion where the processing liquid flows and a portion where the liquid or gas introduced from the outside flows are blocked by a minute gap between the valve body and the valve box. The apparatus for producing a silicon dioxide film according to claim 1, which is characterized in that. 3. In the switching valve, a portion through which the processing liquid flows and a portion through which the liquid or gas introduced from the outside flows are blocked by an O-ring mounted on the valve body side or the valve box side. The apparatus for producing a silicon dioxide film according to claim 1, characterized in that.